Field of Invention
The invention relates to a display panel.
Related Art
The display panel is popularized and matured in technology nowadays, and recently the development direction thereof is towards the higher resolution, lower power consumption and larger size. One of the factors that affects the resolution is the uneven surface of the color filter material, which will cause a reduced transmittance. Furthermore, the above factor will also become more prominent when the pixel size is getting smaller and smaller (i.e. the smaller interval of the black matrix).
FIG. 1A is a schematic enlarged diagram of a second substrate of a conventional display panel, and FIG. 1B is a schematic enlarged diagram of the region A1 in FIG. 1A.
As shown in FIGS. 1A and 1B, the conventional display panel at least includes a first substrate (not shown), a display medium (not shown), a second substrate S2, a black matrix B and a color filter material C. The color filter material C is disposed between the black matrix B by corresponding to each of the pixel areas (not shown). It is clear from the figure that the color filter material C has a height difference at the overlap of the color filter material C and the black matrix B, and the height difference at the overlap of the color filter material C and the black matrix B will result in the scattered light. Therefore, if the height difference at the overlap of the color filter material C and the black matrix B has a larger proportion of the color filter material C, the transmittance will be reduced more.
By taking a full HD product as an example, the ratio of the flat portion to bulge portion is about 86/14 for the portion of the color filter material C corresponding to a single sub-pixel. Moreover, for the WQHD product having a higher resolution and a smaller sub-pixel than the full HD product, the ratio of the flat portion to the bulge portion for the portion of the color filter material C corresponding to a single sub-pixel will be reduced to 82/18. Furthermore, for the recently developed 4K2K product of high resolution, the ratio of the flat portion to the bulge portion for the portion of the color filter material C corresponding to a single sub-pixel will be even reduced to 72/28.
So, due to the increased resolution and less size of sub-pixel, the bulge C1 of the color filter material C at the vicinity to the black matrix B will become more significant for the transmittance.
In addition to the above problem, the smaller sub-pixel (smaller interval of the black matrix) also will cause the developer solution to be easily left between the black matrixes during the process, and therefore the photoresist will be hard to be completely clean and the carbon will be left. This problem also affects the transmittance of the display panel.
Therefore, it is an important subject to provide a display panel with the black matrix structure which can achieve a higher transmittance, when applied to a high-resolution product, and a reduced amount of the carbon remaining between the black matrixes during the process.